Figure 1

Inner ear defects in the TCre-KO. At E15.5, a paint-filled inner ear of a control embryo (A) displays a cochlea (c) consisting of 1.75 turns and a vestibular system consisting of the saccule (s), utricle (u), endolymphatic duct (ed) and lateral, posterior and superior semicircular canals (lsc, psc, ssc). A transverse section though the inner ear of an E17.5 control embryo (B) displays the sensory structures of the ear with an intact organ of Corti (bracketed in inset) and the surrounding capsule. Bone and cartilage staining of an E17.5 control embryo (C) reveals the vestibular capsule (vc) and cochlear capsule (cc). Paint-fill of the inner ear of an E15.5 TCre-KO embryo (D) reveals malformations of both the auditory and vestibular system. The cochlea is severely shortened, the vestibular structures are hypoplastic and the endolymphatic duct (which did not completely fill with paint in (A)) is enlarged. At E17.5, the inner ears of TCre-KO embryos (E) are malformed and display only the hook region of the cochlea (c) with no recognizable organ of Corti (inset), and hypoplastic semicircular canals (lsc, ssc). Bone and cartilage staining (F) reveals a malformed cochlear capsule (cc), while the vestibular capsule (vc) appears relatively unaffected. Scale bar in B is 200 μm.